@tanman: read the thread before you buff my claims
http://www.smashboards.com/showthread.php?t=234203
and for the record, you cant crawl under arrows, bananas, peanuts, pikmin, wolf's laser, mario's fireball, bowser/charizards flame, ivysaur's leaf, pikachu's electricity, lucario's auro sphere and rob's laser/gyro (im sure i left a few out), which make up the majority of projectiles in the game. read the boards and youll see snake normally has to try and force an approach from these characters, cause approaching is really really difficult. the problem is, so is nade camping.
Read what I said: 'I know that won't work against every character' Some of those you listed are pretty particular though/Negligible - Even Snake should be able to get past a 'zard flame or Bowser breath/Throw a nade, and the aura sphere only counts when it's charged...
I'm not saying he's not got a hard Learning curve, I know he does - But what I'm saying is, at the HIGHEST level of play, it's easier for him than alot of the other members of the cast, due to HAVING that potential to be at that level.
Plus 'Good' 'Great' Etc. are all very generalised terms. I'd say my Snake is 'Good' but does he do any proper 'nade camping? No. He plays like my Sonic - Down throw tech chases and dash attacks. Would he beat a Great Snake? Possibly. A Pro one? Doubtful. An actual objective measurement would need to be used to calculate the worth of one's Snake, before this discussion would actually have any merit.
It all depends how much/what kind of a learning curve we're speaking of, and the type of player. An aggressive player will have a hard time 'learning' a defensive character, and vice versa, since it goes against instincts. Arguably, some AT's are alot harder than others, so do we measure by them? Or are we measuring style of play? Overall? And to what level of play? Decent? Competitive? Pro competitive? Perfect Competitive? The steepness varies for all, but at Pro/Perfect level play, if you're at that level, learning characters shouldn't be a problem at all.
And as far as I can tell, the topic's a debate - No clearly defined list, although there's general consensus on certain characters, Snake, Ice Climbers, Diddy... In terms of quantifiable AT's and mindgames though, Yes, Snake rates highly; so yes, he could very well be the 'steepest' learning curve - but that's still only to a point. Throw in Vs. Character, and it's a whole new board game.
In short, I don't want to do my Uni essay, so I wasted everyone's time writing through my thought processes - Yay! Oh, and this is no way a hate on you/Snake players - I respect your skill, and have no doubt it took a decent amount of effort to get there.